The invention relates to an apparatus for examining bodies through scanning by means of ultrasound comprising an ultrasonic applicator consisting of at least one row of adjacently disposed ultrasonic transducer elements and an actuating system for the purpose of actuating the transducer elements individually or in groups, whereby the actuating system for actuating the transducer elements of the ultrasonic applicator is constructed in such symmetrical configurations with an even-numbered and an odd-numbered count of transducer elements that the symmetry axes of the configurations of simultaneously energized transducer elements, at one time, become placed in the gaps between two adjacent transducer elements, and, at another time, in the centers of the transducer elements, whereby the actuation proceeds in such a manner that, in the course of the scanning cycle over the entire length of the applicator, the symmetry axes occupy, at least once, every possible position in the gaps between the two transducer elements, and in the centers of the transducer elements, respectively, with the possible exception of only the transducer elements of the first half of the first, and the second half of the last transducer element group of the applicator.
In the apparatus according to the U.S. application Ser. No. 799,970, the complete sequential pulsing cycle of the transducer elements of the ultrasonic array (e.g. according to FIG. 2) proceeds, in a predetermined scanning pattern, in groups with a higher and in groups with a lower number of transducer elements, whereby each connected group, in unchanged formation, is both transmitter as well as receiver of the echo signals of the ultrasonic pulses expressly radiated by this group. Thus, since switching over takes place, in the cadence of additional transmitting/receiving cycles, between groups with a higher and lower number of transducer elements, the sonic field travel path in the object to be examined varies according to the clock pulse of the transmitting/receiving cycles, and varying echo intensities are obtained per ultrasonic scan line. However, conditioned by this effect, echo pulses of a homogeneous boundary layer are recorded on the viewing screen of a cathode ray tube which has been brightness (or light intensity) modulated by the echos, said echo pulses being recorded thereon as a structure with varying brightness (or light intensity).